Jökull - 01.01.2014, Side 45

Magnetostratigraphy, K-AR dating and erosion history of Hafrafell, SE–Iceland
Figure 3. Detailed geological division of Hafrafell into formations (HF1–HF39) and groups. – Berggrunnskort
af Hafrafelli, greining jarðlaga í Hafrafelli í myndanir (HF1-HF39).
Erosion surfaces in Hafrafell
A total of 12 erosion surfaces are defined for the
Hafrafell section: HR1 to HR12 with stratigraphic lo-
cation shown in Figures 3 and 4 and Table 1. The
lowest surface, HR1, may record the onset of the ice
age in SE Iceland. This lowest erosion surface is lo-
cated in a quarry by the parking lot at the south tip
of Hafrafell. The surface, HR1, is represented by
a 12.5-m-thick sedimentary sequence that occurs be-
tween two tholeiite lava flows of formations HF1 and
HF3 (Figure 4, profile HP1). Upward the sequence is
divided into 6 units, A to F, (Figure 7).
Figure 4. Correlation of stratigraphic profiles in Hafrafell. Formation name, HF1 to HF39, appears next to each
column, and erosion surfaces, HR1 to HR12, are indicated with red lines connecting through columns. Profile
name, e.g. HL, HS or HAF, is provided at the top of each stratigraphic column. Age determinations appear next
to dated units. Lava units drilled for paleomagnetic work are indicated with magnetic signature. Distances (m)
between profiles are given at base of figure. – Tenging milli jarðlagasniða í Hafrafelli. Heiti myndunar, HF1
til HF39, er sýnt til hliðar við hvert snið ásamt rofflötum, HR1 til HR12 sem tengjast með rauðum línum á milli
sniða. Heiti sniðs er sýnt efst í sniði, t.d. HL, HS eða HAF. Aldur er sýndur til hliðar við aldursgreinda einingu.
Segulstefna eininga er sýnd til hliðar við boraðar einingar vegna bergsegulmælinga. Fjarlægð á milli sniða
(m) er sýnd neðst.
JÖKULL No. 64, 2014 45